(CBS) SIMI VALLEY, Calif. - Homicide detectives announced Thursday they have taken over the case of missing Fox executive Gavin Smith after his car was found in Ventura County, Calif., CBS Los Angeles reports.

A tip led Los Angeles County Sheriff's Dept. detectives to Gavin Smith's Mercedes Benz, which was found at a Simi Valley storage facility on Feb. 21.

Smith, 57, was last seen leaving a friend's house in Oak Park, Calif. between 9 p.m. and 10 p.m. on May 1, 2012 in his black 2000 Mercedes E 420.

"Based upon the condition of the vehicle and information we have now gleaned from cooperating witnesses, we are calling his case a homicide," Los Angeles County Sheriff's Dept. Lt. Dave Dolson told the station.

The storage facility where the car was recovered has been linked to Canoga Park resident John Creech, who is currently in custody at the Men's Central Jail on an unrelated narcotics conviction, authorities said.

According to an E! News report, Creech's wife, Chandrika, and Smith were involved in a romantic relationship after meeting in therapy in 2008.

Homicide detectives are seeking the public's assistance in identifying anyone involved in moving the car to the storage facility in the Simi Valley area on or around May 8, 2012.

Smith was an executive in Fox's movie distribution division.

Smith's family - his wife and three sons - has offered $20,000 for information leading to his whereabouts. They also established the web page FindGavinSmith.com.

Anyone with information is asked to contact the Sheriff's Homicide Bureau at (323)890-5500.